Electromagnetic feeding device



Aug. 14, 1951 J. R. LocKER ETAL 554,533

ELECTROMAGNETIC FEEDING DEVICES Filed Oct. 12, 1948 2 Sheets-Sheet l ATTORNEY Aug. 14, 1951 J. R. LocKER UA1.

ELECTROMAGNETIC FEEDING DEVICES 2 Sheets-Sheet 2 Filed Oct. l2. 1948 INVENTORS JAMES REGINALD LOCKER A AND JOHN HALlFA'( WHITELOCK ATTORNEY Patented Aug. 14, 1951 UNiTED STATES PATENT oEFicE 2,564,538 ELECTROMAGNETIC FEEDING DEVICE Jais Reginald Lock Whitelo'ck, Warr Application october 12 In Great Brit .electrical equipment for an electro-magnetic `vibrator which will satisfy the oicial standards laid Adown for flame-proof machinery. Y

Witha vibratory motor as hitherto applied to itswork, not too much care has been necessary to prevent the vibratory parts moving laterally of the direction of vibration, during their vibration, so` longas the Vwidth of the air gap .between the magnet and the armature, in the direction of vibration has been correct. With a flameproof device however, where Vthe vibrations are generated lwithin a name-proof casing, and yet have to be appliedto mechanism exterior to that casing, `it is essential that there be not more than ,a specified maximum clearance laterally of the direction of vibration, between the said Vcasing and that part of the vibratory mechanism which passes through it. Therefore, lateral movement of theecasingv or of thevsaid part which passes throughnit must be avoided.

The object of the present invention, in its broadest aspect, is to provide a vibratory motor, having amagnet and armature within a flameproof casing, the armature being connected to VVrearztion springs external to the casing, wherein all the vibrating parts are mounted so as to have their centre line, in the direction of vibration, fixed relatively to the casing. This means that the portion of the vibrating parts which passes rthrough the wallof the casing may have the least possible vradial clearance with that wall, say not more than .0047, since there is no movement laterally of the opening in the casing.

-A representative example lof the invention is illustrated in the accompanying drawing, where- Y Fig. 1 is a part-sectional elevation of the complete vibrator; Y Y

Fig. 21s a plan of the same; and

Fig. 3 is a sectional elevation of a detail party vshowing the lead-in for the electrical connections.

In general structure the vibrator comprises a main Vframe l, vwhich is at the right-hand end in 'the drawing, carrying the springs for the armature of an electro-magnet 'and adapted to be mounted to the member to be 'vibrated (not shown), which may be for example a bin, deck, platform, 'conveyor or the like; a central casing 2 vof generally-tubular form, with end flanges 2a and longitudinal ribs 2b; and a cap-like end casing 3, having end anges 3a and adapted to form ei-baa Jo'hjil Halifax ington, 'England 194s, seriaLNo. 54,004

ain May 1, 194s 4 claims. (C1. fraaie@ a vclosure for the Vsaid central casing 2. The caing 3 Acarries the frame and coils of the electro-magnet, whilst the casing 2 carries apartition, described below, through which the desired connection between the internal and external vibratry parts may be made, and which is intended to isolate from the outer atmosphere 'any 4sparking which m'ayo'c'cur within the casing.

I-n vgreater detail, the frame l is of rectangular vShape in plan and has t'wo longer cross members 4 joined'at the ends by two'shorter end `members 5, these last being apertured horizontally at 5a to receive the ends of an assembly of nat springs f6, the centre portions of which lie within the central cavity of the frame. There are integral top and bottom plates 5b at the ends of the frame and fon to the top plates are formed integral inclined lugs 5c which vmay be drilled and tapped to receive screwed studs by which the frame I may be suspended from a support. Similar'` lugs 5d on vthe bottom plates 5b 'of the frame 4servefior a viioor mounting for the vibrator, if required.

The ends of the springsG are ground tofsize widthwise and lengthwise. The widthwise grindingle fsuch that the springs just nt the aperture `5a andare not free to move up and down in that aperture, whilst the endwise grinding is such that the plates l secured to the outer ends of the frame l abut against the ends of the springsto prevent any lengthwise movement of the springs. The springs `ii are clamped in position in the apertures 5a by means of the screws 8.

Carried on the centre part of the assembly7 of springs yis a clamp 9, the rear end of whichv is formed as or carries'an extensionv l0 Vwhereby* it vmaybe attached to the member to be vibrated,

such as a conveyor deck, barrel packer, binbr the like. The bracket 9 and the left-hand spring E are provided with a mutually-"engaging socket and projection lformation so as to prevent any v relative lateral movement of the clamp'with respect to the springs. If desired, all the springs may have mutually-engaging parts to assist Vin the prevention of relative lateral movement between spring an'd spring. Thisa'ccurate 'securingof the ends o/f'the springs in the frame, and ofthe clamp on the centre of the springs, results yijn the 'centre line of the vibratory mass being x'ed in space. y

The forward 'end of the clamp 9 isV of reduced. size to V"e'iit'e'r the adjacent end of the central casing 2. Within such casing is 'a partition Il having a central opening 2v therein, surroundedrb'y a b'os's I2'a,rthrugh which,openingpasseslthe shaft ,la extending from the clamp 9. This shaft lf3 is s hwn as inte-gral with the 'Clamp 9,v but it could.

I5. The relative diameters of the shaft I3 and the opening I2 are such that the radial clearance between the shaft and the wall of the opening doesf not :exceed va-specied maximum, for example .004", so that any sparking which may occur within the left-hand portion of the cham-- ber may not pass through the partition I2 to the explosive atmosphere.

laminated poles which lie opposite the said arma;

ture I5. This magnet is adjustable axially of the' i i casing by means of the adjustment screws-I1 lso that the width of the air gap between the magnet and the armature may be varied withinfine limits. The central parts of the casing is provided with sight holes I8, covered by removable `plates I0 opposite the air gap. I i

" The 'electric leads from the mains are received fby a terminal member 20 fromwhich connection is made Within the closed boX 2l to the outer end jo'f a"l,e ad"in member 22, iwhose inner end is within 'th'e'casing (see Fig. 3) and from such inner end of the Vlead-in member are the leads 23 to the coils of the magnet I6. An insulating' bush `'hijsurroundsjthe member 22, and insulating washers 2% take the thrust of the clampingY nuts In the assembling of the apparatus, in .order to ensure` the desired fixity of alignment, the 1 4 springs f5 'are'first located inthe frame l and are clamped in position, after which the bracket Sis secured in place on the springs. This determines the constancy of thecentre lineof Athe vibrating parts;

Thereupon the central part 2 of the casing is fixed in position on the frame I,

with the shaft I3 projetcing concentrically through the opening I2 'and when these parts are located in accurate relativepositions and secured therein by studs 2a they are dowelled together by means of do'wells 2b (see Fig. 2) so as to ensureV that, after any subsequent removal and replacement of the part 2, the axial alignment will be unaffected. Next, the armature carrier I4 is attached to the protruding end of the shaft I3,

the magnet iii is` secured within the part 3 of the casing, and such part is then bolted against the flanged end of the central casing 2. Constant axial, alignment. between the magnet and the .armature is not essential, provided the air gap is within the prescribed limits, but it is essential that thecentral part 2 Vof the casing and the clamp 9, on the springs be in constant alignment to ensure thatthe radial clearance around the shaft I3 is not excessiveat any. point in the circumference.

If desired, a flexible diaphragm or Ibellows member may be provided around the shaft I3 Vwith one edge clamped to the shaft and the other edge clamped to the partition I2.

What we claim is: l

1. An electro-magnetic vibrator foiuse in explosive atmospheres comprising a completely enclosed casing, an electro-magnet secured therein at one end, an armature for said electro-magnet in the other end of said casing, said casing having an openingin said other end, a shaft secured to said armature and passing through and substantially lling said opening, said shaft adapted to vibrate longitudinally in said opening, a frame having. one end fixed to said casing adjacent' to lsaid shaft, a set of superposedflat springs in said frame with the faces of said springs transverseof the axis of said shaft, means xed to said frame 'andcvontacting the ends of said springs to render y :A

,Y shaft non-shiftable relativeA to said frame.

' 2. An electroemagnetic v'ibrator'fon use in eX- plosive atmospheres comprising a completely enclosed casing, an electro-magnet secured therein at one end, an armature for said electro-magnet Y Y. .l inthe other end of said casing, said casing` hav- Carried within the outer part-3 of thecasing l, is a high-frequency 2-pole magnet I'h'aving lsaid shaft adapted to vibrate longitudinally in saidopening, a frame having one end fixed to said casing adjacent to said shaft, a setl of super- -posed flat springs in said frame with the faces of said springs transverse of the axis-of Ysaid shaft, means fixed to said frame and' contacting the Yends of said springs to render them non-shiftable, and a clamp around said springs and fixed to said shaft, rendering said shaft non-shiftable relative to said frame.

3. An electro-magnetic vibrator for use in explosive atmospneres comprising a completely enclosed casing, an electro-magnet secured therein at one end, an armature for said electro-magnet in the other end of said casing, said casing'having an opening in said other end, a shaft secured to saidv armature and passingthrough and substanm tially filling said opening, said casing being split transversely to the axis' of said shaft, means for securing together the parts so formed "of said casing, said electro-magnet being heldin one of said parts and said armature being held in the other ofysaid parts, said shaft adapted to vibrate longitudinally in said openinga frainehaving one end fixed to said casing adjacenttosaid at one end, an armature for said electrornagnet in the other end of saidcasing, said casing having an opening in said other end, a shaft secured to said armature and passing through and substan= tially filling said opening and lfiavingaA clearance of not over .004 inch, said shaft adapted to'vibrate longitudinally in said opening, a frame having one end fixed tosaid casing adjacent to said shaft, a set of superposed fiat springs in said frame with the faces of said springs' transverse of une axis of said shaft, means nxed'to said ifo frame and contacting the ends of said 'springs to render them non-shiftable, and a clamp around said'springs and fixed to said shaft, rendering said shaft non-shiftable relative-i150 said frame.

, JAMES RECHNAI'JD'LACKEI?)j JOHN HALIFAX WHITELOCK.

'REFERENCES CITED Y The following references are of record in the Vfile of this patent:

,TENTS y UNITED STATES'P V"Number Name Y f Date 1,362,049 Starker Dec. 14, 1920 V.9..,1 53,24=3 Flint ".1Apr. 4, 1939 

